Composition of soluble indigestible fibre and of microalgae used in the well-being field

ABSTRACT

Described is the use of soluble indigestible fiber for inducing lysis of the cell walls of eukaryotic microalgae in the lumen of the intestine of an omnivorous or carnivorous animal including an intestinal flora and also for synergistically increasing the effect of the indigestible fiber in the induction of the growth of the intestinal flora of an omnivorous or carnivorous animal. The subject matter of the invention is also the composition intended for this use and for a method of improving the health or of food supplementation.

The present invention relates to the use, in combination, of solubleindigestible fibers and of at least one eukaryotic microalga in thewell-being field, in food supplementation, and in improving thedigestion and the health of nonruminant animals.

Owing to their common feeding habits, the intestinal flora ofnonruminant animals, namely carnivorous and omnivorous animals, iscomposed of bacterial strains of the same genera. Beyond this, thisflora changes according to the age and the diet of the host. In humans,the gastrointestinal tract is constituted of a complex microbialecosystem (10¹³ to 10¹⁵ bacteria/g), with a predominance of Bacteroides,Bifidobacteria and Eubacteria. The microorganisms form a microbiotawhich exercises numerous biochemical and physiological functions, inparticular (i) a supplement to nutrient fermentation, (ii) a barriereffect in order to protect the digestive system against pathogenicbacteria, (iii) a stimulation in the development of the immune system.

This microbiota is constituted of more than 500 different known species.The members of the Bacteroides genus represent from 25% to 60% of thebacterial population in the intestine of an adult human being (MooreW-E-C., 1978) (Finegold S-M., 1983).

The prior art indicates that glycanase activities appear to be encodedby certain strains colonizing the intestinal mucosa.

Bacteroides thetaiotamicron appears to encode 172 glycosylhydrolases,Bifidobacterium longum has only 39 of them. However, in vitro, only theexpression of certain enzymes has been described. In addition, thisexpression appears to be inducible (Salyers A A et al., 1977, KopecnyJ., et al., 2004; Robert C. et al., 2007).

Thus, induction of the intestinal flora can be demonstrated by measuringthese glycolytic activities such as, in particular, α- and(β-glucosidases, (β-galactosidase, cellobiohydrolase and β-xylosidase(Marteau Ph. et al., 1990).

It is acknowledged that indigestible fibers favorably affects the healthby acting at the intestinal level on the beneficial microflora(Schrezenmeir J., 2001) or by repressing colonization by pathogenicbacteria (Rastall R-A., 2000). The potential of said fibers can alsoconsist of a preventive or curative effect against certain diseases(cardiovascular diseases, cancers) or against dysfunctions of theintestine (IBS).

Certain “indigestible” fibers, mainly fibers that cannot be hydrolyzedby the enzymes synthesized by nonruminant animals, mainly carnivores andomnivores, are soluble. By way of example, mention may be made ofinulin, dextrins, galactooligosaccharides (GOSs), solubleoligosaccharides of oleaginous or proteaginous origin,fructooligosaccharides (FOSs), fructan, glucooligosaccharides,polydextrose, pectin, lactosucrose and branched maltodextrins. Thesesoluble fibers are fermentable; in other words, they are fermented bythe intestinal bacterial flora of the host, namely of carnivorous oromnivorous animals. The fermentation releases short-chain fatty acids inthe colon, which have the effect of reducing the pH of the colonicmedium and, consequently, of limiting the development of pathogenicbacteria.

The term “soluble fibers” is intended to mean fibers that are soluble inwater. The fibers can be assayed according to various AOAC methods. Byway of example, mention may be made of the AOAC methods 997.08 and999.03 for fructans, FOSs and inulin, AOAC method 2000.11 forpolydextrose, AOAC method 2001.03 for assaying the fibers contained inbranched maltodextrins, or AOAC method 2001.02 for GOSs and also solubleoligosaccharides of oleaginous or proteaginous origin.

Eukaryotic microalgae, which represent a particular class of plants,comprise in their wall, in addition to cellulose, cellulose/mannancopolymers, chitosan and chitin.

The polysaccharide walls of eukaryotic microalgae are insoluble and arerelatively unfermented by the intestinal flora of nonruminant animals.They are therefore indigestible by omnivores and carnivores such asmammals, and in particular humans.

The polysaccharide walls of eukaryotic cells are the opposite of thoseof prokaryotics, namely bacteria or cyanobacteria, which themselves areconstituted of peptidoglycans having completely distinct structures andproperties.

Plants and fungi constitute at the same time a considerable nutritionalpotential and also a source of antioxidants such as lutein, selenium,carotenoids or chlorophyll for plants.

However, owing to the poor digestibility of their polysaccharide wallsfor omnivores, carnivores and in particular humans, only a smallproportion of these nutrients or antioxidants is released into the lumenof the intestine.

Thus, a substantial part of the nutrient intake from plants and fungi isnot released and therefore not absorbed during digestion. This problemtakes on an entirely different importance in the case of a diet that ispredominantly or even exclusively plant-based.

Although constituting an important source of nutrients, some plants arevery rarely consumed, as is the case of algae. Among the algae, adistinction is made between macroalgae and microalgae.

Microalgae, and in particular the viridiplantae, the labyrinthulids, thehaptophytes, the rhodophytes and the alveolates, represent a large groupthat is potentially a supplier of compounds having exploitablebiological activities, such as proteins, the richness of which can rangeup to 70% by dry weight of the microalgae. Mention may also be made ofvitamins, in particular vitamins A, B1, B2, B6, B12, C, E, folic acid orpantothenic acid, or pigments capable of having a positive effect on thehealth, such as an antioxidant effect for chlorophyll, carotenoids orphycobiliproteins.

Phycobiliproteins are water-soluble photosynthetic pigments. They arefound in phycobilisomes in rhodophyceae, and also free in the thylakoidlumen in Cryptophyceae.

Mention may be made of phycocyanin, the antioxidant activity of whichappears to be six times greater than a reference antioxidant compoundsuch as Trolox® (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid)and 20 times greater than that of ascorbic acid or vitamin C.

For the above reasons, plants and also fungi are used as constituents ofchoice for food supplements. However, in order for their metabolites tobe accessible and assimilable, an extraction by cell lysis is generallyrecommended.

The techniques conventionally used are physical techniques by boiling, amethod which has the drawback of degrading the heat-labile constituents,such as vitamins for example.

There are also chemical techniques using solvents such as phenol, formicacid or urea. The drawback of the latter method is the removal of thesolvent after cell lysis and the need for a verification of the nontoxicnature of the lysates obtained. This toxicity can be induced by thepresence of compounds derived from unwanted chemical reactions with thesolvent or induced by the solvent.

Enzyme lysis of the walls of microalgae can be envisioned, but imposesstrict conditions, whether in the production of the active enzymes or inthe purification thereof, according to the means of production selectedand the purpose of the final product. Finally, the choice of the enzymesand the determination of the optimum reaction conditions can require alaborious setting up operation, before conditions enablingreproducibility of the reaction are obtained.

In addition, the lysis and the elimination of the cell walls wouldreduce the properties of these eukaryotic cells in terms of improvingthe health and in particular in terms of combating enteropathogenicdiseases.

Specifically, microalgae are described as having beneficial propertieswith respect to intestinal health. Thus, they would be particularlyrecommended in the treatment of the various enteric syndromes, such asinfantile gastroenteritis or diarrhea, etc. In fact, theirpolysaccharide wall appears to allow the adsorption of toxinssynthesized by the enteropathogenic bacteria.

In addition, microalgae appear to be involved in health protectiongenerally by adsorbing xenobiotics such as mycotoxins, dioxins or PCBs.Beyond the toxicity induced by the permeability of the intestinalbarrier to xenobiotics and the passage thereof into the blood, thesetoxins appear to be also involved in numerous intestinal diseases owingto the attack on both the intestinal mucosa and the flora.

The ingestion of algae without prior lysis induces protection of theintestine with respect to enteropathogenic bacteria and xenobiotics.However, in view of the agents synthesized by each of thesemicroorganisms, this protective effect on intestinal health is reducedin comparison with the real protective potential thereof.

This is because, in addition to the effect induced by their cell wall,these microorganisms, such as the microalgae Chlorella vulgaris,Chlorella saccharophila, Scenedesmus, Chlamydomonas reinhardtii orDunaliella salina, appear to be capable of expressing antioxidantagents, for example superoxide dismutase.

However, the prior art does not describe a method of administration ofthese eukaryotic organisms with a polysaccharide wall contained in thebolus or provided as a supplement which is at the same time a) easy toobtain, i.e. without particular preparation, purification or extraction,b) which constitutes a provision of directly assimilable nutritionalagents and c) which induces a protective effect on the health ofcarnivorous or omnivorous animals which is concomitantly improved andbroader (i) owing to the properties of the cell walls while at the sametime having (ii) a massive release of active protective enzymes or ofprotective agents which have not been denatured or degraded by priorpassage through the stomach.

In order to solve these various problems of the prior art, the inventionrelates to a composition comprising one or more eukaryotic microalgaeand one or more soluble indigestible fibers.

A synergistic effect of this mixture has been demonstrated (i) in thestimulation of the intestinal flora, (ii) in the production of enzymesby this intestinal flora, and (iii) in the protection of intestinalhealth by massive release of active agents such as, in particular,antioxidants or of inhibitors of pathogenic agents by lysis of themicroalga.

The microalgae alone do not enable such an increase in the flora norsuch a release of their intracellular content. Likewise, theindigestible fibers alone do not enable such an increase in theintestinal flora.

The use of soluble indigestible fibers combined with eukaryoticmicroalgae makes it possible to obtain an improvement in intestinalwell-being by increasing the flora by a degree greater than the simpleuse of soluble indigestible fibers. In addition, this mixture makes itpossible at the same time to provide nutrients that can be used by theflora, maintaining and intensifying the induction of the growth thereof,while providing active agents and nutritional agents that can beassimilated by the intestine owing to the very release of thecytoplasmic content of the organism with a polysaccharide wall.

The applicant has demonstrated the synergistic effect of this mixtureboth in the growth of the flora and in the lysis of the microalgae.Thus, according to the microalga selected, its effect on the health canbe targeted. This effect may be the fact of a provision of antioxidantssuch as selenium, superoxide dismutase, carotenoids, vitamins,chlorophyll or phycobiliproteins, or of a provision of detoxifyingagents, anti-inflammatory agents, or inhibitors of the adhesion ofpathogenic agents (bacteria, viruses, parasites). The desired effect maysimply be intestinal well-being owing to an increase in the flora, saidincrease being greater than that observed with simple absorption ofindigestible fibers alone.

The particularly advantageous nature of this composition does not lie inthe simple addition of a soluble indigestible fiber to a microalga, andtherefore does not lie in the simple addition of the effects of each ofthe compounds of the mixture. In fact, it is a real cooperation betweenthese two compounds of the mixture, with a synergistic effect beingobtained in the induction both of the growth of the flora and of theexpression of glycolytic enzymes. This effect is the consequence of twounexpected and consecutive effects. The first is the induction of theexpression of glycolytic enzymes directed against the walls of themicroalgae, in sufficient amount to induce a first cell lysis. Thesecond effect is surprising in that, through a massive provision of wallresidues and nutrients, the lyzed cells intensify both the growth of theflora and the induction of the expression of glycolytic enzymes.Surprisingly, these same enzymes will be responsible for maintainingthis phenomenon by inducing a massive lysis of the cells that havemaintained their integrity.

When absorbed alone, microalgae are considered by the prior art to beindigestible for humans and also for the other omnivorous or carnivorousanimals, and therefore barely assimilable or not at all. They do nottherefore, alone, lead to a stimulation of the synthesis of glycolyticenzymes of the flora. On the other hand, surprisingly, the compositionaccording to the invention resolves this problem and can therefore beused as a food supplement since the nutrients contained in themicroalgae are, according to the invention, released into the lumen ofthe intestine and therefore become available to be assimilated or activewith respect to the flora or to the intestinal mucosa. A method formaintaining or improving intestinal health, comprising a step ofabsorption of the composition according to the invention, is effectivein particular with respect to enteric syndromes or to cancers related tothe various attacks on the flora or on the intestinal mucosa bypathogenic agents, free radicals or xenobiotics. Specifically, thegrowth of the flora observed is greater than with compositionscomprising only indigestible fibers. This composition according to theinvention can be indicated alone or as a supplement in the prevention ortreatment of intestinal syndromes, of intestinal cancers or ofintestinal inflammations. It can also be envisioned to take this mixturein order to improve the digestibility and therefore the bioavailabilityof nutrients of plant origin, indigested independently by an individual.

Advantageously, the indigestible soluble fibers are chosen fromdextrins, galactooligosaccharides (GOSs), fructooligosaccharides (FOSs),oleaginous or proteaginous oligosaccharides, fructan, inulin,polydextrose, glucooligosaccharides, lactosucrose, branchedmaltodextrins and mixtures thereof.

These molecules intensify, owing to their atypical and varied linkages,induction of the various hydrolytic enzymes of the intestine flora. Thisphenomenon is all the more substantial in the case of branchedmaltodextrins.

Among the soluble oligosaccharides of oleaginous or proteaginous origin,mention may be made of soya, rapeseed or pea, the solubleoligosaccharides of which are particularly advantageous by virtue of thepresence of varied oligosaccharide linkages.

An increase in the production, by the intestinal flora, ofα-glucosidase, of β-glucosidase, of β-galactosidase, of esterase, ofcellobiohydrolase and of β-xylosidase following ingestion of thecomposition according to the invention has been demonstrated. Theseenzymes are markers of a considerable induction in the flora associatedwith an increase in mass of the flora, which is a sign of concomitantgrowth of said flora. Thus, the particularity of the compositionaccording to the invention is the presence of these organisms whichserve both as substrates for the enzymes produced and therefore asinducers of growth of the flora, but also as inducers of the productionof glycolytic enzymes in combination with the soluble indigestiblefibers. The composition according to the invention makes it possible tospecifically induce glycolytic enzymes capable of hydrolyzing the wallsof plants and fungi, and in particular walls of algae and of yeasts.Thus, this broad spectrum of application enables the compositionaccording to the invention to be adaptable to the desired effect, and tothe deficiency to be made good.

Preferably, the eukaryotic microalgae are advantageously chosen from theviridiplantae, the labyrinthulids, the haptophytes, the rhodophytes andthe alveolates, and the combination thereof, preferably the chlorophytaand the labyrinthulids, and the combination thereof, and even morepreferably Chlorella, Scenedesmus, Dunaliella, Haematococcus,Schizochytrium and Thraustochytrium, and the combination thereof.

The advantageous effect of the microalgae is linked to their unicellularnature and to the relatively easy conditions for cultivating them. Thus,these organisms can be used without prior treatment, without thecreation of waste, and in their entirety. Unlike plants having a stem,all the dry matter can be used: there are no parts that are unusableowing to a characteristic inherent in a cell differentiation, in aspecialization of an organ or in a reduction in expression of a protein.

According to the invention, the lysis of the microalgae enables amassive release of their intracellular content, which is not observed inthe case of the use of the microalga alone. These microalgae areparticularly indicated for their ability to bind toxins, and for theirrichness in antioxidants, but also in nutrients. This use thereforemakes it possible to optimize the effect observed during the absorptionalone of a microalga.

These microalgae are particularly nutritive by virtue of their richnessin proteins, and in long-chain omega-3 polyunsaturated fatty acids,compared with land plants.

Advantageously, the composition according to the invention comprises, inaddition to the microalgae, at least one other eukaryotic organism witha polysaccharide wall, chosen from fungi, plants and mixtures thereof.The fungus that is preferred according to the invention is a yeast.Preferably, the composition comprises a ratio by weight of microalgaealone or as a mixture with another eukaryotic organism with apolysaccharide wall/indigestible soluble fibers ranging from 5/95 to90/10.

According to one advantageous variant, the composition according to theinvention comprises branched maltodextrins having:

-   -   between 15% and 35% of 1→6 glucosidic linkages, preferably        between 22% and 45%, more preferably between 27% and 34%,    -   a reducing sugar content of less than 20%, preferably between 2%        and 20%, more preferably between 3% and 16%, even more        preferably between 3% and 12%,    -   a polydispersity index of less than 5, preferably between 0.5        and 4, more preferably between 1 and 3.5, and    -   a number-average molecular mass Mn at most equal to 4500 g/mol,        preferably between 600 and 4000 g/mol, more preferably between        1000 and 2700 g/mol.

The linkages contained in these fibers appear to be very structurallyclose to those found in the cell walls of eukaryotic cells and couldfacilitate the induction of the flora in the synthesis of enzymesdirected against their walls.

The indigestible soluble fibers/eukaryotic organisms with apolysaccharide wall mixtures which are preferred are branchedmaltodextrins and/or polydextrose in combination with eukaryoticmicroalgae such as Chlorella, Schizochytrium, Thraustochytrium ormixtures thereof.

By way of illustration, about 2 to 100 g of indigestible soluble fibersfor 0.3 to 20 g of microalgae will preferably be administered per dayfor a human being, preferably 5 g to 20 g of indigestible soluble fibersfor 1.5 g to 6 g of microalgae per day, for a ratio by weight ofmicroalgae/indigestible soluble fibers ranging from 5/95 to 90/10,preferably from 20/80 to 80/20, and more preferably from 25/75 to 75/25.The microalgae can be taken alone or as a mixture with anothereukaryotic organism with a polysaccharide wall.

According to the invention, the composition comprises 0.5% to 30%,preferably 5% to 15% by dry weight of the combination of indigestiblesoluble fibers/microalgae alone or in a mixture with another eukaryoticorganism with a polysaccharide wall.

The oral administration may be isolated, as a treatment of several daysor several weeks, or may be chronic.

The composition according to the invention is preferably in a formchosen from solid forms, in the form of a powder, a tablet or asuppository, or liquid forms, in the form of an emulsion or a syrup.

Advantageously, the composition in accordance with the invention may bein a ready-to-use form in solid form such as, for example, in the formof a powder, a tablet or a suppository, or else in liquid form, in theform of an emulsion or a syrup, or in the form of a beverage, such as afruit juice, or a soup, or else in the form of yoghurts or incorporatedinto breakfast cereals.

The oral administration preparations may comprise any customaryexcipient or carrier. They may consist of powders, granules, solutions,or the like, and, optionally, incorporate other medicinal ingredients oractive ingredients.

Advantageously, the composition in accordance with the invention mayalso comprise at least one active agent or one nutrient intended for theprevention and/or treatment of intestinal syndromes such as irritablebowel syndrome, or traveler's diarrhea, of intestinal inflammations, ofchronic inflammatory bowel diseases, of intestinal cancers or ofdiet-related diseases, the prevention of age-related diseases, foodsupplementation, induction of the intestinal flora, increasing theresistance to physical exertion, improving the digestibility ofnutrients of plant origin, and obtaining a protective effect on theintestinal health of an omnivorous or carnivorous animal.

According to another aspect of the present invention, the compositionaccording to the present invention can be used as a medicament.

Advantageously, the composition according to the present invention canbe used for the prevention and/or treatment of intestinal syndromes suchas irritable bowel syndrome or traveler's diarrhea, of intestinalinflammations, of chronic inflammatory bowel diseases, of intestinalcancers or of diet-related diseases, the prevention of age-relateddiseases, and food supplementation, in particular in the case ofdeficiencies, in an omnivorous or carnivorous animal.

According to another aspect of the present invention, the compositionaccording to the present invention can be used nontherapeutically forinducing the intestinal flora, increasing the resistance to physicalexertion, improving the digestibility of nutrients of plant origin,obtaining a protective effect on intestinal health, and foodsupplementation, in a healthy omnivorous or carnivorous animal.

Advantageously, the invention also relates to a method for controlledand localized release of nutrients or of active agents in the colon ofan omnivorous or carnivorous animal comprising an intestinal flora, saidmethod comprising a step of concomitant or simultaneous ingestion ofeukaryotic microalgae containing said nutrients or active agents and ofindigestible soluble fibers. The ingestion of the indigestible solublefibers and of the eukaryotic microalgae induces lysis of the cell wallsof the microalgae in the lumem of the intestine of the animal. Thus,this method makes it possible to increase the digestibility of themicroalgae, and to potentiate their effects on the health, while at thesame time increasing their nutritional potential.

Preferably, the eukaryotic microalga are genetically modified or derivedfrom a selection. The term “active agents” is intended to mean protein,glycan or biochemical agents or nucleic acids which have a beneficialeffect on the health, such as antioxidant enzymes or molecules, enzymesor molecules having an anti-inflammatory effect or an inhibitory effectwith respect to certain microorganisms that synthesize enteropathogenicingredients, or molecules which protect the intestinal flora or theintestinal mucosa.

Moreover, the invention also relates to a method of induction of thegrowth of the intestinal flora of an omnivorous or carnivorous animaland/or of food supplementation for an omnivorous or carnivorous animal,comprising a step of concomitant or simultaneous ingestion of at leastone microalgae in combination with indigestible fibers.

The invention also relates to a method for maintaining and/or improvingthe health of an omnivorous or carnivorous animal, consisting of a firststep of administering soluble indigestible fibers and a second,concomitant or separate, step of administering at least one microalga,alone or in combination with a eukaryotic organism with a polysaccharidewall, preferably chosen from plants, fungi and a combination thereof.

A subject of the invention is also a method of food supplementation foran omnivorous or carnivorous animal, comprising a first step ofadministering indigestible soluble fibers and a second, concomitant orseparate, step of administering at least one microalga, alone or incombination with a eukaryotic organism with a polysaccharide wall,preferably chosen from plants, fungi and a combination thereof.Advantageously, the fungus chosen is a yeast.

The invention also relates to a kit for the therapeutic or prophylactictreatment of an omnivorous or carnivorous animal, comprising:

-   a) a first composition according to the invention; and-   b) a second composition comprising at least one active agent or one    nutrient.

Preferably, the active agent is an agent intended for the induction ofthe intestinal flora, for the treatment of intestinal syndromes orcancer, for food supplementation or for the prevention of age-relateddiseases or of metabolic syndromes, or of chronic inflammatory boweldiseases, in an omnivorous or carnivorous animal.

Said composition according to the invention can be used in humans, butalso in animals, and more particularly in cats, dogs, pigs, rabbits orthe other animals which are sensitive to intestinal inflammation,animals exhibiting a reduction in their immunity, or animals of whichthe activity or the resistance to physical exertion requires a supply ofnutrients, such as racehorses or racing dogs. Said composition can beenvisioned as a food supplement for animals bred outside their naturalenvironment, such as fish, for example.

This composition is proposed for food supplementation for preventing orsupplementing the treatment of diet-related or age-related diseases, ofmetabolitic syndromes, inflammatory bowel diseases (or IBDs), orsyndromes such as irritable bowel syndrome, or for the prevention of orthe treatment of individuals suffering from traveler's diarrhea,abdominal pain of which the etiology is often unknown, individualssuffering from or subject to dietary deficiencies, such as vegetariansor vegans, or even elderly individuals, or individuals whose health isfragile or who are convalescing.

Finally, said composition is particularly suitable for stressedindividuals whose stress manifests itself at the intestinal level.

The invention will be understood more clearly upon reading the exampleswhich follow and which are nonlimiting illustrations.

EXAMPLE 1

The effect of various soluble or insoluble fibers on the glucosidaseactivities of the intestinal flora in laboratory rats is studied. Thesoluble fibers are branched maltodextrins according to the invention,FOSs and polydextrose, and the insoluble fibers are cellulose fibers.

The branched maltodextrins chosen in this example have between 15% and35% of 1→6 glucosidic linkages, a reducing sugar content of between 2%and 5%, a polydispersity index of less than 5 and a number-averagemolecular mass Mn of between 2000 and 3000 g/mol:

Reducing sugars 2.3 Mn (g/mol) 2480 Mw (g/mol) 5160 1,2-linkage (%) 101,3-linkage (%) 12 1,4-linkage (%) 49 1,6-linkage (%) 29

They also have a total fibers content of 90% on a dry basis, determinedaccording to the AOAC method (No. 2001-03).

40 OFA rats of Sprague Dawley origin are divided up into 4 groups whichare fed with a diet of which the details are given in table 1 below.

Group 4 receives a diet supplemented with fructooligosaccharides (FOSs)(Raftilose® P95 sold by the company Orafti).

Groups 5 and 6 receive a diet supplemented, respectively, withpolydextrose and cellulose.

TABLE 1 Batch Food and product tested 1 AO4C food 2 AO4C food + 10%glucose 3 AO4C food + 10% branched maltodextrins 4 AO4C food + 10% FOSs5 AO4C food + 10% polydextrose 6 AO4C food + 10% cellulose

After one week of isolation during which the animals receive a standarddiet and drinking water, the rats consume the food for 36 days.

On D₀, the animals are given no food for 24 hours. They are given drinkad libitum. On D₁, the feces are collected.

The diet described in table 2 is given to the animals.

On D₂₈, the animals are given no food for 24 h. Drink is given adlibitum.

On D₂₉, the feces are again collected.

On D₂₆, the animals are sacrificed.

A general macroscopic observation of the organs is performed. The cecaare ligatured and removed. The full ceca, the cecal contents and theempty ceca are weighed.

The enzyme activities of the feces are also evaluated (α-glucosidase andβ-glucosidase).

Table 2 gives the enzyme activities of the feces determined,respectively, on D₀ and D₂₉.

TABLE 2 D₀ D₂₉ α-glucosidase β-glucosidase α-glucosidase β-glucosidase(Uabs/min/g (Uabs/min/g (Uabs/min/g (Uabs/min/g Batch of feces) offeces) of feces) of feces) 1 3.23 ± 1.17 4.40 ± 2.86 5.62 ± 1.24 6.08 ±1.39 2 3.19 ± 1.72 3.86 ± 2.03 5.97 ± 2.60 6.74 ± 3.38 3 3.37 ± 1.852.55 ± 1.11 23.09 ± 7.29  24.21 ± 9.10  4 3.10 ± 1.37 2.94 ± 1.19 15.32± 3.91  9.94 ± 3.05 5 3.15 ± 1.67 2.64 ± 1.10 13.22 ± 4.03  10.02 ±2.94  6 3.22 ± 1.64 3.55 ± 2.10 6.08 ± 2.02 6.68 ± 2.98

On D₀, the activities of the batches are identical to the controlbatch 1. On D₂₉, the glucosidase activities are very greatly increasedby the administration of 10% of branched maltodextrins. On the otherhand, a smaller increase is observed for the animals receiving 10% ofFOSs or of polydextrose. In the case of cellulose, no significantincrease is observed.

Specifically, increases of 310% and of 298% are observed for,respectively, α-glucosidase and β-glucosidase of the batch receivingbranched maltodextrins compared with the control batch, whereas theincreases are, respectively, only 172% and 63% for the FOS batch and135% and 64% for the polydextrose batch.

The branched maltodextrins have characteristics that are much moreadvantageous than the FOSs or the polydextrose and allow a much greaterinduction of the glucosidase activity. On the other hand, the insolublefibers have, themselves, no effect on the glucosidase activity.

EXAMPLE 2

The metabolism of a microalga, Chlorella, and a fungus, yeast, wasstudied in rats in comparison with a branched maltodextrin (BMD) andwith polydextrose (POLY) for 28 days. The BMD and the polydextrose wereidentical to those of the previous example. In parallel, the Chlorellaeor yeasts were combined with the branched maltodextrin in order to studythe effects of the combination of a eukaryotic organism with apolysaccharide wall and of a soluble indigestible fiber.

The products tested are introduced into a standard food for laboratoryrats in a proportion of a fixed dose of 5%, alone or as a mixture withanother product, according to table 3 given below.

TABLE 3 Batch No. Products tested Batch 1 (control) — Batch 2 (C) 5% ofChlorellae Batch 3 (BMD) 5% of BMD Batch 4 (Y) 5% of yeasts Batch 5(BMD + C) 5% of BMD + 5% of Chlorellae Batch 6 (BMD + Y) 5% of BMD + 5%of yeasts Batch 7 (POLY) 5% of POLY Batch 8 (POLY + C) 5% of POLY + 5%of Chlorellae Batch 9 (POLY + Y) 5% of POLY + 5% of yeasts

The Chlorella tested is a Chlorella vulgaris. The yeast tested is aSaccaromyces cerevisiae.

After one week of quarantine during which the animals receive a standarddiet and drinking water, the rats are randomized on the basis of theirweight and assigned to a study batch.

The rats participating in this study are male OFA rats of Sprague-Dawleyorigin. Their weight is between 100 and 125 g upon reception. They arehoused in pairs in Makrolon cages.

During the study, various parameters are evaluated: clinicalobservation, weight change, food consumption, drink consumption.

On D-1 and D20, the animals are placed individually in a metabolism cagefor 24 hours. During this period, they receive no food, but receivedrinking water ad libitum.

On D0 and D21, the 24-hour feces are collected. They are weighed wet andimmediately frozen at −20° C. They will subsequently be freeze-dried fora period of 48 to 72 hours, weighed dry after freeze-drying, and ground.The various analyses will be carried out within 24 hours on these groundfeces.

On D14, feces are collected directly from the anus of the animals. Aminimum amount of 3 grams is collected for each animal. These feces areweighed wet and then frozen immediately at −20° C. while awaitinganalysis.

On the freeze-dried feces (collected at D-1 and D20), the enzymeactivities of the α-glucosidases, β-glucosidases, β-galactosidases,esterases, cellobiohydrolases and β-xylosidases are carried out by meansof the spectrophotometric method. The substrates used are, respectively:p-nitrophenyl-α-D-glucopyranoside, p-nitrophenyl-β-D-glucopyranoside,p-nitrophenyl-β-D-galactopyranoside, p-nitrophenyl acetate,p-nitrophenylcellobioside and p-nitro-phenylxylopyranoside. Beforequantifying these enzyme activities, the enzymes are extracted by meansof a succession of agitation, centrifugation and washing steps. Theenzyme activity results are expressed in unit of absorbance per minute(or hour for the cellobiohydrolase and β-xylosidase activities) and pergram of dry feces.

On the frozen feces (collected on D14), the antioxidant activity isdetermined by the TEAC (Trolox Equivalent Antioxidant Capacity) assaymethod. The objective of this test is to generate a free radical (ABTS•+which is blue-green in color) from a mixture of a solution of colorlessABTS with potassium persulfate. The discoloring of the free-radicalspecies by the reaction with the antioxidants of the feces tested makesit possible to determine an overall antioxidant capacity. Thisdiscoloration is monitored by spectrophotometry. The results areexpressed as percentage TEAC inhibition compared with a negative controlwhich does not cause discoloration.

The statistical analysis of the results was carried out by means of avariance homogeneity test (Bartlett's test) followed by an analysis ofvariance by ANOVA if the result was nonsignificant or a Kruskall andWallis test and a Mann-Whitney test if the result was significant. Thebatches were compared with one another and relative to the controlbatch. Only the following comparisons will be presented:

-   -   Batch 1 (control) versus all the batches    -   Batch 5 (BMD+C) versus batch 2 (C)    -   Batch 5 (BMD+C) versus batch 3 (BMD)    -   Batch 6 (BMD+Y) versus batch 4 (Y)    -   Batch 6 (BMD+Y) versus batch 3 (BMD)    -   Batch 8 (POLY+C) versus batch 2 (C)    -   Batch 8 (POLY+C) versus batch 7 (POLY)    -   Batch 9 (POLY+Y) versus batch 4 (Y)    -   Batch 9 (POLY+Y) versus batch 7 (POLY).

In the tables, a number is noted: it indicates the batch with respect towhich the result is significant. The symbols T, *, **, *** indicate thedegree of significance, respectively: tendency, p<0.05, p<0.01, p<0.001.

The results show that the weight change, the food consumption and thedrink consumption change identically between the batches. No particularclinical observation was observed during the study.

TABLE 4 Batch α-Glc β-Glc β-Gal esterases CBH β-Xyl 1 control 6.6 ± 1.49.2 ± 2.5 28.2 ± 7.8 121.3 ± 33.0 158.8 ± 78.9 319.9 ± 95.5  2 C 7.7 ±1.8 9.1 ± 2.9 28.0 ± 7.7 121.6 ± 33.6 127.9 ± 53.9 311.6 ± 61.6  3 BMD7.1 ± 1.5 9.2 ± 2.8 26.0 ± 7.9 110.9 ± 27.2 156.7 ± 50.4 344.9 ± 122.1 4Y 7.5 ± 2.0 10.6 ± 4.2  27.7 ± 6.3 114.4 ± 21.2 161.6 ± 69.5 360.6 ±120.2 5 BMD + C 7.1 ± 1.7 10.4 ± 3.1  26.1 ± 8.4 113.9 ± 22.6  183.3 ±100.3 398.2 ± 139.6 6 BMD + Y 6.5 ± 0.8 7.6 ± 3.0 23.4 ± 7.9 103.6 ±28.8  90.9 ± 48.8 250.3 ± 93.4  7 POLY 6.9 ± 1.3 8.7 ± 2.1 25.0 ± 6.2115.0 ± 35.2 150.0 ± 53.9 302.1 ± 97.7  8 POLY + C 7.2 ± 0.9 9.4 ± 1.327.0 ± 7.1   121 ± 29.7 141.7 ± 50.9 315.7 ± 101.2 9 POLY + Y 7.4 ± 1.59.1 ± 2.3 28.0 ± 7.9 111.3 ± 27.9 125.1 ± 60.7 334.6 ± 115.5

The results of the enzyme activities of the α-glucosidases (α-Glc),β-glucosidases (β-Glc), β-galactosidases (β-Gal), esterases,cellobiohydrolases (CBH) and β-xylosidases (β-Xyl) measured on D0 aresummarized in table 4.

The statistical analysis of these data does not show any significantdifferences between the batches. At the beginning of the study on D0,the animals of the various batches all have the same baseline in termsof fecal enzyme activities. The results of the enzyme activities of theα-glucosidases (α-Glc), β-glucosidases (β-Glc), β-galactosidases(β-Gal), esterases, cellobiohydrolases (CBH) and β-xylosidases (β-Xyl)measured on D21 are summarized in table 5.

TABLE 5 Batch α-Glc β-Glc β-Gal esterases CBH β-Xyl 1  6.7 ± 1.4  9.3 ±3.1 27.5 ± 10.4 111.5 ± 24.2 170.2 ± 66.1 332.6 ± 129.2 Control stat3***- 3***- 5***- 5***-6***- 3**- 4^(T)-5**- 4***- 4**- 6***- 8*** 4***-6**-8* 5***- 5***- 8*** 5***- 6***- 6***-7*- 6***- 8**-7* 8*** 7**-8** 2C  6.7 ± 2.4 11.5 ± 4.4 22.7 ± 4.5  99.2 ± 18.8 191.0 ± 66.0 245.5 ±71.3 stat 5***- 5***-8** 5***-8** 5***-8** 5***- 5***-8** 8*** 8** 314.4 ± 5.7 22.1 ± 7.2 28.4 ± 10.6 101.6 ± 21.8 544.7 ± 270.3 391.4 ±98.3 BMD stat 1***- 1***-5*- 5***- 5***-6***- 1**-5*- 5*-6**- 5^(T)-6**6**-7** 6***-8** 8** 6**-8** 8* 4 Y 11.8 ± 2.3 16.3 ± 3.8 31.4 ± 8.3123.0 ± 19.4 327.8 ± 78.5 435.2 ± 126.5 stat 1***- 1**-6*** 6*** 6**1***- 1^(T)-6* 6*** 6*** 5 18.9 ± 4.8 31.4 ± 7.1 56.3 ± 11.3 162.9 ±26.8 792.6 ± 169.4 593.2 ± 226.5 BMD + C stat 1***- 1***- 1***-1***-2***- 1***- 1**- 2***- 2***-3*- 2***- 3***-7*** 2**-3*- 2***-3*-3^(T)-7* 7*-8* 3***- 7* 7* 7**-8^(T) 6 34.6 ± 14.1 42.9 ± 15.6 56.4 ±11.5 170.0 ± 26.9 989.3 ± 208.6 647.4 ± 208.9 BMD + Y stat 1***- 1***-1***- 1***-3***- 1***- 1**-3**- 3**- 3**- 3***- 4**-7** 3**- 4*-7**4***- 4***-7* 4***-7** 4***- 7** 7** 7  9.2 ± 2.2 14.7 ± 2.7 28.1 ± 7.8110.9 ± 29.7 321.2 ± 104.7 353.7 ± 57.2 POLY stat 1*-5*- 1*-3**-5**-6**- 5***-8*- 1**-5*- 5*-6**- 6**-9* 5*-6**- 8* 6** 6**-8*8^(T)-9^(T) 8^(T)-9^(T) 8 15.2 ± 3.7 26.2 ± 5.4 44.7 ± 3.4 145.8 ± 28.7521.3 ± 93.5 501.9 ± 74.3 POLY + C stat 1**- 1***- 1***- 1***-2**- 1**-1*-2**- 2*** 2**-5*- 2**-3**- 3**-7* 2**- 3*-7^(T) 7^(T) 5^(T)-7*3**-5*- 7* 9 16.4 ± 3.5 27.7 ± 7.2 43.1 ± 4.1 140.7 ± 33.3 601.7 ± 111.1500.7 ± 54.7 POLY + Y stat 1**-7* 1**-4^(T)- 1***- 1***-3***- 1**-1*-3**- 6*-7^(T) 3***-4** 4**-6* 3**- 4*-6*-7^(T) 4***- 6**

Table 6 below represents the multiplication factor of the enzymeactivities of the various batches in comparison with batch 1 (control).The value represents the ratio: (enzyme activity of a givenbatch)/(enzyme activity of the control batch).

A result greater than 1 therefore shows that the enzyme activity of thegiven batch is greater than the enzyme activity of the control batch.

TABLE 6 Batch α-Glc β-Glc β-Gal esterases CBH β-Xyl 2 C 0 1.23 0.83 0.881.12 0.73 3 BMD 2.14 2.37 1.03 0.91 3.20 1.17 4 Y 1.76 1.75 1.14 1.101.92 1.30 5 BMD + C 2.82 3.37 2.04 1.46 4.65 1.78 6 BMD + Y 5.16 4.612.05 1.52 5.81 1.94 7 POLY 1.37 1.58 1.02 0.99 1.89 1.06 8 POLY + C 2.272.81 1.62 1.31 3.06 1.51 9 POLY + Y 2.45 2.98 1.57 1.26 3.54 1.51

Table 7 below represents the multiplication factor of the enzymeactivities of the “branched maltodextrin+Chlorellae” batch in comparisonwith the “branched maltodextrin” and “Chlorellae” batches, or themultiplication factor of the “polydextrose+Chlorellae” batch incomparison with the “polydextrose” and “Chlorellae” batches. The valuerepresents the ratio: (enzyme activity of the “producttested+Chlorellae” batch)/(enzyme activity of the “product tested”batch) or the ratio: (enzyme activity of the “product tested+Chlorellae”batch)/(enzyme activity of the “Chlorellae” batch).

TABLE 7 Batch α-Glc β-Glc β-Gal esterases CBH β-Xyl (BMD + C)/C 2.822.73 2.48 1.64 4.14 2.41 (BMD + C)/BMD 1.31 1.42 1.98 1.60 1.45 1.51(POLY + C)/C 2.27 2.28 1.97 1.47 2.73 2.04 (POLY + C)/POLY 1.65 1.781.59 1.31 1.62 1.42

Table 8 below represents the multiplication factor of the enzymeactivities of the “product tested+yeasts” batch in comparison with the“product tested” and “yeasts” batches. The value represents the ratio:(enzyme activity of the “product tested+yeasts” batch)/(enzyme activityof the “product tested” batch) or the ratio: (enzyme activity of the“product tested+yeasts” batch)/(enzyme activity of the “yeasts” batch).

TABLE 8 Batch α-Glc β-Glc β-Gal esterases CBH β-Xyl (BMD + Y)/Y 2.401.94 1.98 1.67 1.81 1.65 (BMD + Y)/BMD 2.93 2.63 1.79 1.38 3.01 1.48(POLY + Y)/Y 1.39 1.70 1.37 1.14 1.83 1.15 (POLY + Y)/POLY 1.78 1.881.53 1.27 1.87 1.42

For the α-glucosidase, β-glucosidase and cellobiohydrolase activities,the statistical analysis shows that the activities of all the batches,except the “Chlorellae” batch, increase significantly compared with thecontrol batch. If the “Chlorellae” batch is excluded, the multiplicationfactor of the activities is between 1.37 and 5.16 (α-glucosidases),between 1.58 and 4.61 (β-glucosidases) and between 1.02 and 5.81(cellobiohydrolases) compared with the control batch.

These activities are statistically greater for the “branchedmaltodextrin+Chlorellae” batch in comparison with the “branchedmaltodextrin” batch alone or with the “Chlorellae” batch alone. Themultiplication factors are, respectively, 1.31-2.82 for theα-glucosidase, 1.42-2.73 for the β-glucosidase, and 1.45-4.14 for thecellobiohydrolase.

Similarly, these activities are statistically greater for the “branchedmaltodextrin+yeasts” batch in comparison with the “branchedmaltodextrin” batch alone or with the “yeasts” batch alone. Themultiplication factors are, respectively, 2.40-2.93 for theα-glucosidase, 1.94-2.63 for the β-glucosidase, and 1.81-3.01 for thecellobiohydrolase.

For the β-galactosidase, esterase and β-xylosidase activities, the“branched maltodextrin+Chlorellae” and “branched maltodextrin+yeasts”batches experience a statistical increase in their activities comparedwith the control batch. For these two batches, the multiplication factorof the activities is 2.04/2.05 (β-galactosidases), 1.46/1.52 (esterases)and 1.78/1.94 (β-xylosidases) compared with the control batch.

These activities are statistically greater for the “branchedmaltodextrin+Chlorellae” batch in comparison with the “branchedmaltodextrin” batch alone or with the “Chlorellae” batch alone. Themultiplication factors are, respectively, 1.98-2.48 for theβ-galactosidase, 1.60-1.64 for the esterase, and 1.51-2.41 for theβ-xylosidase.

Similarly, these activities are statistically greater for the “branchedmaltodextrin+yeasts” batch in comparison with the “branchedmaltodextrin” batch alone or with the “yeasts” batch alone. Themultiplication factor are, respectively, 1.98-1.79 for theβ-galactosidase, 1.67-1.38 for the esterase, and 1.65-1.48 for theβ-xylosidase. All the results are less marked for the polydextrosetested alone or as a mixture with Chlorella or the yeasts.

In order to prove that the products have a synergistic effect and not acumulative effect, table 9 below represents the difference in enzymeactivity calculated between a given batch and the control batch. The“theoretical results” have been calculated on this same table:

-   -   the theoretical activity of batch 5 represents the sum of the        activity obtained for batch 2 plus the activity of batch 3;    -   the theoretical activity of batch 6 represents the sum of the        activity obtained for batch 3 plus the activity of batch 4;    -   the theoretical activity of batch 8 represents the sum of the        activity obtained for batch 2 plus the activity of batch 7;    -   the theoretical activity of batch 9 represents the sum of the        activity obtained for batch 7 plus the activity of batch 4.

Table 9 clearly shows that, irrespective of the enzyme activitymeasured, the activities obtained for the products tested as a mixtureare very much greater than the theoretical enzyme activities calculated.The effects are therefore synergistic effects and not additive effects.

TABLE 9 α-Glc β-Glc β-Gal esterases CBH β-Xyl 2 C 0 2.2 −4.8 −12.3 20.8−87.1 3 BMD 7.7 12.8 0.9 −9.9 374.5 58.8 4 Y 5.1 7.0 3.9 11.5 157.5102.6 5 BMD + C 12.2 22.1 28.8 51.4 622.4 260.6 5 7.7 15.0 −3.9 −22.2395.3 −28.3 theoretical BMD + C 6 BMD + Y 27.9 33.6 28.9 58.5 819.1314.8 6 12.8 19.8 4.8 1.6 532.1 161.4 theoretical BMD + Y 7 POLY 2.5 5.41.0 −0.6 151.0 21.1 8 POLY + C 8.5 16.9 17.2 34.3 351.1 169.3 8 2.5 7.6−3.8 −12.9 171.8 −66.0 theoretical POLY + C 9 POLY + Y 9.7 18.4 15.629.2 431.5 168.1 9 7.6 12.4 4.9 10.9 308.5 123.7 theoretical POLY + Y

In order to demonstrate the cell lysis of the microorganisms, ananalysis of an intracellular marker was carried out. As opposed toyeast, Chlorella is described as containing many antioxidants such aschlorophyll and vitamins, for example. A study of this marker specificfor the lysis of Chlorella, in the feces of both rats having ingestedchlorella (batches 2 and 5) and rats having ingested yeasts (batches 4and 6), makes it possible to distinguish the lysis of chlorella from anyother artefactual effect not specific to the eukaryotic organism,chlorella or yeast, associated with the fiber.

The results of the antioxidant activities of the feces measured on D14are summarized in table 10.

TABLE 10 Batch % inhibition 1 409.7 ± 28.6 control stat 5*** 2 C 413.9 ±37.6 stat 5*** 3 BMD 426.1 ± 43.4 stat 5** 4 Y 380.6 ± 23.6 stat — 5BMD + C 497.0 ± 51.9 stat 1***-2***-3** 6 BMD + Y 419.5 ± 30.5 stat — 7POLY 422.4 ± 37.9 stat — 8 POLY-C 451.7 ± 52.2 stat — 9 POLY + Y 430.9 ±32.1 stat —

The antioxidant capacity of the feces of the animals of the “branchedmaltodextrin+Chlorellae” batch is statistically increased compared tothe control batch, compared to the “branched maltodextrin” batch andcompared to the “Chlorellae” batch.

The multiplication factors for the “branched maltodextrin+Chlorellae”batch are:

-   -   1.21 compared with the control batch    -   1.20 compared with the “chlorellae” batch    -   1.16 compared to the “branched maltodextrin” batch.

The results obtained for the polydextrose are much less accentuated.

In order to prove that the products have a synergistic effect and not acumulative effect, table 11 below represents the difference inantioxidant capacity calculated between a given batch and the controlbatch. The “theoretical results” have been calculated on this sametable:

-   -   the theoretical activity of batch 5 represents the sum of the        antioxidant capacity obtained for batch 2 plus the antioxidant        capacity of batch 3;    -   the theoretical activity of batch 6 represents the sum of the        antioxidant capacity obtained for batch 3 plus the antioxidant        capacity of batch 4.

TABLE 11 % inhibition 2 C 4.2 3 BMD 16.4 4 Y −29.1 5 BMD + C 87.3 5theoretical BMD + C 20.6 6 BMD + Y 9.8 6 theoretical BMD + Y −12.7 7POLY 12.7 8 POLY + C 42.0 8 theoretical POLY + C 16.9 9 POLY + Y 21.2 9theoretical POLY + Y −16.4

This table clearly shows that the antioxidant capacity obtained for thebranched maltodextrin/chlorellae mixture is very much greater than thetheoretical antioxidant capacity calculated. The effects are thereforesynergistic effects and not additive effects. This observation is notvalid for the BMD+Y batch.

These results clearly show that hydrolysis of the Chlorella wall enablesthe release of the antioxidants, whereas this is not observed for theanimals consuming Chlorella alone.

In order to support the observations made on the BMDs, other BMDs weretested (table 12) and similar results were obtained.

TABLE 12 BMD1 BMD2 BMD3 Mn (g/mol) 1189 1232 2504 Mw (g/mol) 3996 40044602 Mn/Mw 3.4 3.2 1.8 1,6-linkage 33 32 31-35 Reducing 10.4 9.6 4.1sugars

These results are extremely interesting since they demonstrate asynergistic, and not additive, effect between the eukaryotic microalgaesuch as Chlorella and the insoluble indigestible fibers. Although thebranched maltodextrins show a much greater effect, other solubleindigestible fibers, such as polydextrose, induce a synergistic effectin the same way. Thus, the applicant has shown, by studying the enzymeactivities in the feces of the rats, a synergistic effect of the mixtureof soluble indigestible fibers and eukaryotic organisms with apolysaccharide wall on the growth of the intestinal flora. The applicanthas also shown, by studying the antioxidant activities of the feces, asynergistic effect of the mixture of soluble indigestible fibers andeukaryotic organisms with a polysaccharide wall on the lysis of theorganisms with a polysaccharide wall, the antioxidant effect of thecomposition containing microalgae being much greater than that of theyeast. In all probability, the mechanism would be as follows: thebacteria of the intestinal flora, subsequent to the induction owing tothe ingestion of the mixture, would secrete enzymes capable ofhydrolyzing the wall of the Chlorellae and of the yeasts, releasingvarious compounds, in particular nitrogenous compounds, that promote thegrowth of other bacteria which will themselves produce enzymes.

Salyers A A, Palmer J K, Wilkins T D. Laminarinase (beta-glucanase)activity in Bacteroides from the human colon. Appl Environ Microbiol.1977 May; 33(5): 1118-24.

Robert C, Chassard C, Lawson P A, Bernalier-Donadille A. Bacteroidescellulosilyticus sp. nov., a cellulolytic bacterium from the human gutmicrobial community. Int J Syst Evol Microbiol. 2007 July; 57 (Pt 7):1516-20.

Kopecný J, Hajer J, Mrázek J. Detection of cellulolytic bacteria fromthe human colon. Folia Microbiol (Praha). 2004; 49(2): 175-7.

Marteau P, Pochart P, Flourié B, Pellier P, Santos L, Desjeux J F,Rambaud J C. Effect of chronic ingestion of a fermented dairy productcontaining Lactobacillus acidophilus and Bifidobacterium bifidum onmetabolic activities of the colonic flora in humans. Am J Clin Nutr.1990 October; 52(4): 685-8.

The invention claimed is:
 1. A composition comprising one or moreeukaryotic microalgae and one or more soluble indigestible fibers,wherein said one or more eukaryotic microalgae comprising entire cellswith polysaccharide walls that have not been subjected to prior lysis,said one or more soluble indigestible fibers comprise branchedmaltodextrins that have: between 15% and 50% of 1,6-glucosidic linkages,a reducing sugar content of between 2% and 12%, a polydispersity indexof less than 5, and a number-average molecular mass Mn at most equal to4500 g/mol.
 2. The composition as claimed in claim 1, wherein said oneor more soluble indigestible fibers further comprise solubleindigestible fibers selected from the group consisting of dextrins,galactooligosaccharides (GOSs), fructooligosaccharides (FOSs),oleaginous or proteaginous oligosaccharides, fructan, inulin,polydextrose, glucooligosaccharides, lactosucrose, and mixtures thereof.3. The composition as claimed in claim 2, wherein the oligosaccharidesof oleaginous or proteaginous origin are soya, rapeseed or pea solubleoligosaccharides.
 4. The composition as claimed in claim 1, wherein themicroalgae are selected from the group consisting of viridiplantae,labyrinthulids, haptophytes, rhodophytes and alveolates, andcombinations thereof.
 5. The composition as claimed in claim 1, furthercomprising, in addition to the microalgae, at least one other eukaryoticorganism with a polysaccharide wall that has not been subjected to priorlysis, selected from the group consisting of fungi and plants, andmixtures thereof.
 6. The composition as claimed in claim 5, wherein thefungus selected is a yeast.
 7. The composition as claimed in claim 1,wherein the composition comprises a ratio by weight of microalgae aloneor as a mixture with another eukaryotic organism with a polysaccharidewall/indigestible soluble fibers ranging from 5/95 to 90/10.
 8. Thecomposition as claimed in claim 1, wherein the composition is in a solidform selected from the group consisting of a powder, a tablet and asuppository, or a liquid form selected from the group consisting of anemulsion and a syrup.
 9. The composition as claimed in claim 2, whereinthe microalgae are selected from the group consisting of viridiplantae,labyrinthulids, haptophytes, rhodophytes and alveolates, andcombinations thereof.
 10. The composition as claimed in claim 3, whereinthe microalgae are selected from the group consisting of viridiplantae,labyrinthulids, haptophytes, rhodophytes and alveolates, andcombinations thereof.
 11. The composition as claimed in claim 2, whereinthe composition comprises, in addition to the microalgae, at least oneother eukaryotic organism with a polysaccharide wall that has not beensubjected to prior lysis, selected from the group consisting of fungiand plants, and mixtures thereof.
 12. The composition as claimed inclaim 3, wherein the composition comprises, in addition to themicroalgae, at least one other eukaryotic organism with a polysaccharidewall, selected from the group consisting of fungi and plants, andmixtures thereof.
 13. The composition as claimed in claim 4, wherein thecomposition comprises, in addition to the microalgae, at least one othereukaryotic organism with a polysaccharide wall that has not beensubjected to prior lysis, selected from the group consisting of fungiand plants, and mixtures thereof.
 14. The composition as claimed inclaim 2, wherein the composition comprises a ratio by weight ofmicroalgae alone or as a mixture with another eukaryotic organism with apolysaccharide wall/indigestible soluble fibers ranging from 5/95 to90/10.
 15. The composition as claimed in claim 3, wherein thecomposition comprises a ratio by weight of microalgae alone or as amixture with another eukaryotic organism with a polysaccharidewall/indigestible soluble fibers ranging from 5/95 to 90/10.
 16. Acomposition comprising: one or more eukaryotic microalgae, said one ormore eukaryotic microalgae comprising entire cells with polysaccharidewalls that have not been subjected to prior lysis; yeast; and one ormore soluble indigestible fibers, wherein said one or more eukaryoticmicroalgae comprise Chlorella microalgae; and said one or more solubleindigestible fibers comprise branched maltodextrins that have: between15% and 50% of 1,6-glucosidic linkages, a reducing sugar content ofbetween 2% and 12%, a polydispersity index of less than 5, and anumber-average molecular mass Mn at most equal to 4500 g/mol.